UFC 137 headliner B.J. Penn fueled by haters and those who would hold him down

Former UFC lightweight and welterweight champion B.J. Penn is too old for this you-know-what.

He's still a proud man and a fighter. But he's a father of two now, and has children to keep in check the flare-ups of emotion that would have landed him in hot water three years ago. He can't go flying off at the handle at any slight. He is measured because he is responsible.

In short, he's an adult. At 32, he ought to be.

Few of the haters that seem to follow him everywhere have undergone such transformation. Even after all these years, they still dole out criticism that attacks his motivation, his skills, his background. And it's those nice people that give him the motivation to do his best in the gym.